list_auth_keys

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the behavioral disclosure burden. It adds meaningful traits: the result includes expired keys, the scope is limited to the authenticated user, and the api_key parameter falls back to the MESS_API_KEY environment variable. It does not discuss output format, but an output schema is present.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two brief sentences, with the primary purpose front-loaded and the parameter explanation following. No filler or redundant restatement of the tool name.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a low-complexity listing tool with one optional parameter and an output schema, the description provides everything an agent needs to select and invoke it: scope, expired-key inclusion, and authentication fallback behavior. No critical gap is apparent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description must explain the parameter. It does: 'api_key: API key. Falls back to MESS_API_KEY environment variable.' This adds the important optionality and fallback semantics that the schema (a nullable field with default null) does not convey.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'List all API keys belonging to the authenticated user, including expired ones.' This clearly states the operation and scope, and distinguishes list_auth_keys from siblings like create_auth_key and delete_auth_key.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The context is clear: use this tool when you need to enumerate the authenticated user's API keys, with the explicit note that expired keys are included. It does not explicitly contrast this with alternative tools or state when not to use it, but the usage context is apparent.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.